The Philips Avent Natural Response nipple supports babies' unique rhythm of sucking, swallowing, and breathing, while the AirFree vent is designed to keep air away from their stomachs, providing extra protection against colic, gas, and reflux. The Avent nipple's wide, soft, and flexible design is intended to mimic the shape and feel of the breast, making it easier for the baby to latch and feed comfortably. This nipple features a unique opening that releases milk only when the baby actively drinks—so when they pause to swallow and breathe, the milk also stops. The AirFree vent is designed to offer feeding comfort by preventing air from entering your little one's belly during upright feeding.